北京市平原区黄庄-高丽营断裂北段土壤气汞地球化学特征

Geochemical characteristics of soil-gas mercury in northern section of Huangzhuang-Gaoliying fault of Beijing plain

选取地表变形痕迹明显的典型场地——温榆河北堤、中部绿化带和北部农田,开展土壤气汞、大气汞浓度和土壤汞含量监测研究。监测结果表明:1)地表覆盖层性质不同,对表层土壤气汞特征有显著的影响,表层(0~20 cm)土壤气汞浓度以及土壤汞(0~20 cm)含量均为绿化带>农田>河堤;2)深层(60~80 cm)土壤气汞浓度高于表层(0~20 cm)土壤气汞浓度,地表变形痕迹明显处为土壤气汞浓度异常地段,其曲线分布形态反映温榆河北堤和北部农田断裂结构特征不同,不同季度深层土壤气汞浓度特征表明黄庄-高丽营断裂带温榆河北堤和北部农田地段活动性相同;3)通过监测土壤气汞地球化学动态特征,有利于土壤气汞地球化学方法进行断裂带的控制性探测。

In the Future Science City Park, which is traversed by the northern section of the Huangzhuang-Gaoliying fault zone,typical sites with obvious surface deformation marks-the north embankment of Wenyu River, the central green belt, and the northern farmland--are selected for monitoring experiments of soil-gas mercury, atmospheric mercury and soil mercury. The monitoring results show that:(1)The different properties of land cover layer have a significant influence on the characteristics of the surface soil-gas mercury and the surface soil mercury, with the green belt > the farmland > the embankment.(2)The concentration of deep soil-gas mercury is higher than that of the surface soil-gas mercury. There are obvious abnormal mercury concentrations in areas with obvious surface deformation traces. The curve peak corresponds well to the fault and the curve shape better reflects the fault properties. The characteristics of deep soil-gas mercury in different seasons show that the activities of the two segments of the fault zone are the same.(3) Monitoring the dynamic characteristics of soil-gas mercury geochemistry is beneficial to controlling detection of fault zones by soil-gas mercury geochemistry method.